55. Diseases of the TMJ: Ankylosis

Question 1

TMJ Ankylosis

Answer 1

• Stiffening of the temporomandibular joint (TMJ)=>
• Abnormal adhesion and rigidity of the condyles to the skull base,

Question 2

TMJ Ankylosis classification

Answer 2

• Fibrous ankylosis=> Proliferation of connective tissue
• Osseous ankylosis=>Proliferation of bony tissue
• False or true ankylosis
• Extra-articular or intra-articular
• Unilateral or bilateral
• Partial or complete

Question 3

Common causes of TMJ ankylosis

Answer 3

• Joint infection=> Secondary to septicemia=>
• Due to conditions like osteomyelitis, septic sore throat, scarlet fever
• Diseases affecting the joints=> rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis
• Trauma=>
• Birth from forceps delivery
• Intrauterine trauma leading to congenital ankylosis
• Facial injuries

Question 4

Clinical features of TMJ ankylosis

Answer 4

• Vary=> severity, time of onset, and duration=>
• Early joint involvement (less than 15 years)=>
• Severe facial deformity and loss of function
• Later joint involvement (after 15 years):
• Marginal or no facial deformity
• Severe functional loss.

-Those developing ankylosis after full growth completion have no facial deformity.

Question 5

Unilateral ankylosis

Answer 5

• Obvious facial asymmetry
• Deviation of the mandible and chin to the affected side
• Cross bite and Class II Angle malocclusion on the affected side with unilateral posterior cross bite on the ipsilateral side
• Absence of condylar movements on the affected side

Question 6

Bilateral ankylosis

Answer 6

• Progressive inability to open the mouth with gradual decrease in interincisal opening
• Symmetrical but micrognathic mandible
• Typical ‘bird face’ deformity with receding chin.
• Class II malocclusion